symptoms of a serious allergic reaction may include: swelling of face, lips, tongue, or throat, fainting or dizziness, very rapid heartbeat, problems breathing or swallowing, severe rash or itching. tell your doctor if you get a lump or swelling in your neck. serious side effects may happen in people who take victoza®, including inflammation of the pancreas (pancreatitis), which may be fatal. stop taking victoza® and call your doctor right away if you have signs of pancreatitis, such as severe pain that will not go away in your abdomen or from your abdomen to your back, with or without vomiting. tell your doctor about all the medicines you take and if you have any medical conditions. taking victoza® with a sulfonylurea or insulin may cause low blood sugar. the most common side effects are nausea, diarrhea, and headache. some side effects can lead to dehydration, which may cause kidney problems. if your pill isn't giving you the control you need ask your doctor about non-insulin victoza®. it's covered by most health plans.